Thallus: crustose, thin or rather thick and then uneven, sometimes cracked or effuse, inconspicuous, often endolithic surface: gray-pink or orange-pink, to pale gray-green or pale yellow, fading in the herbarium Apothecia: usually numerous, sessile, scattered to often heaped or occasionally confluent, round, 0.3-1.2 mm in diam. disc: pale to deep orange or orange-red, at first pore-like, then concave, often shiny margin: entire or with radiate cracks exciple: pale pink or externally pale to brownish yellow and internally hyaline, well developed, smooth, even to +coarsely radiate-striate, crenate, often radiately prolific in the older ones hymenium: hyaline to yellow below, with oil droplets, I+ permanently blue (or I-, according to Thomson, 1997), 110-150 µm tall; paraphyses: 1.5-2 µm wide below, with tips up to 3 µm wide; hypothecium: hyaline asci: cylindrical, (4-)8-spored, with uniseriate or partly biseriate spores, 8-spored ascospores: hyaline, 3septate to muriform when mature, with 3-6 transverse septa and 1-2 longitudinal septa, ellipsoid to narrowly ellipsoid,. (11-)15-25(-40) x 6-10(-16) µm Spot tests: thallus K-, C-, KC-, P- Secondary metabolites: none detected. Substrate and ecology: usually on damp, often sheltered and shaded, calcareous rock or mortar, sometimes spreading to adjacent soil and mosses World distribution: circumboreal-temperate, Northern Hemisphere; Europe, North Africa; North America (mostly eastern, but also reported from British Columbia and California) Sonoran distribution: southern California. Notes: The immature apothecia of Gyalecta jenensis are +spherical prior to the development of the disc and then resemble pale pink perithecia. The thallus is sometimes associated with bright orange tufts of the photobiont (Trentepohlia).